Metal decking punch and method

ABSTRACT

Duct hanger slots or openings are founded in metal decking by means of a punch dropped downwardly against the decking to perporate same. Means to guide and prevent rotation of the punch are also provided. Hangers lowered through the slots have upper ends projecting above the decking to become embedded in poured lightweight concrete.

United States Patent [:91

Militello July 1, 1975 METAL DECKING PUNCH AND METHOD 3, 29, 2 25 3 2 g n t y tlal. 20/366 2 .6 4 l 6 t it 2 I5 [76] Inventor: men! Milken", Ash DH 3,372,523 3/1968 l. 5 2/39 Monterey Park, Calif. 91754 [22] Filed: May 2!, 19 3 Primary ExaminerC. W. Lanham Assistant Examiner-Dan C. Crane 21 A LN .:3 1,997 1 pp R l t d U s A I f D l Attorney, Agent, or FirmW1ll|am W. Haefliger eae pplcalon aa 63] C nt' uat' n f Se. No. 220.046 J t 24, I972, assumes? ABSTRACT Duct hanger slots or openings are founded in metal [52] US. Cl. 29/428; 29/460; 30/366 decking by means of a punch dropped dcwnwardly [5 l llrl. Cl 821d 28/26 against the decking to perporate Same. Means to guide [58] held Search 29/4601 4284 30/366, and prevent rotation of the punch are also provided. 30/368; 52/39 698; 248/58 Hangers lowered through the slots have upper ends projecting above the decking to become embedded in {56] Rderences cued poured lightweight concrete.

UNITED STATES PATENTS 2,161,969 6/1939 Mange r. 30/366 l Claim 11 Draw 1 METAL DECKING PUNCH AND METHOD This is a continuation of application Ser. No. 220.046. filed Jan. 24. 1972. now abandoned.

BACKGROUND OF THE INVENTION This invention relates generally to installation of air ducts in buildings. and more particularly concerns apparatus and method for forming openings in sheet metal decking. in order to receive hangers that support the air ducts.

At the present time it is conventional procedure to attach duct hangers to metal decking as by driving nails or rivets upwardly through the decking and into light weight aggregate or concrete covering the decking. This operation is excessively time consuming as well as undesirably expensive. and in addition requires use of special power tools capable of driving such nails upwardly from beneath the decking. There is need for a more rapid method of attaching the hangers to the decking. and which will require less installation time.

SUMMARY OF THE INVENTION It is a major object of the invention to provide apparatus and method which will meet the above described need. Basically. the decking punching apparatus of the invention comprises:

a. an elongated tubular guide having opposite ends which are open.

b. an elongated metallic rod movable endwise in said guide and a handle on one end of the rod projecting from the guide, and

c. a punch carried at the opposite end of the rod to be punched through the sheet metal at a selected location in response to the momentum of the rod dropping in the guide acting to propel the punch in a direction through the opposite open end of the tube.

As will appear. the tubular guide and rod typically have interengaged guide shoulders extending longitudinally for blocking relative rotation ofthe rod and guide; and a stop on the rod is engageable with a shoulder on the guide to limit relative travel of the rod in the guide in a downward punching direction.

In use. a location is selected for forming a hole or slot in the sheet metal decking. and the punch tip is placed at that location with the rod and guide extending above; the handle is manually lifted while the lower end of the guide is maintained in engagement with the decking proximate that location, the rod is then dropped to develop momentum acting to propel the punch downwardly through the decking to form an opening after which the punch is removed from the opening. and finally a hanger is extended through the opening to be supported and retained at the upper side of the decking as by concrete poured over the deck to embed the hanger upper end. It is found that one workman. using this method. can produce such hanger openings and install hangers therein much faster than by use of conventional methods.

Finally. the punch may have the form of a flat blade to form an elongated slot opening in the decking; or the punch may be of rounded cross section to form a rounded hole.

These and other objects and advantages of the invention. as well as the details of an illustrative embodiment will be more fully understood from the following description and drawings. in which:

DRAWING DESCRIPTION FIGS. 1-4 are side elevations showing the method of use of the invention;

FIG. 2a is a view taken on lines 2a2u of FIG. 2;

FIG. 5 is an enlarged side elevation showing details of the punch;

FIGS. 6-8 are enlarged fragmentary sections;

FIG. 9 is an elevation taken on line 9-9 of FIG. 8; and

FIG. 10 is an enlarged fragmentary section.

DETAILED DESCRIPTION The sheet metal decking punching apparatus. an example of which appears at 10 in FIG. 5, includes an elongated tubular guide (as for example tube or sleeve 11) having opposite open ends 12 and 13; an elongated metallic rod (as for example rod 14) movable endwise in the guide and having a handle 15 on one end of the rod projecting from the guide; and a punch 16 carried at the opposite end of the rod to be punched through the sheet metal at a selected location. as at 17. Such punching is in response to downward momentum developed by the dropping of the rod in the guide 11 acting to propel the punch 16 in a downward direction through the opposite or lower open end 13 of the tubular guide. As seen in FIGS. 5 and 6, the rod may advantageously comprise multiple sections as at 140. I41; and 14c which have pin and box threaded end interconnection. as for example appears at 20 in FIG. 6. Likewise. the sleeve guide 11 may comprise multiple sections as at 11a, 1 lb and which have pin and box threaded end interconnection. as for example appears at 21 in FIG. 6. Accordingly. the tool may be quickly disassembled into its component sections for ease of transportation. In this regard, the overall length of the rod 14 and handle 15 may be around 4 feet. and its diameter about 1 inch. these values being illustrative only.

FIG. 6 also shows the provision of wrench flats 23 on successive guide sections 11b and 116 to facilitate their assembly and disassembly. The guide 11 may consist of aluminum. whereas the rod 14 may consist of steel.

The punch 16 may have the form ofa flat spring steel blade as shown. with a lower tapered tip 160. Upon punching through the decking 26 seen in FIG. 2, an elongated slot 27 is formed through same. The metal decking shown may have corrugated shape. as is known. an example being Robinson" decking. Alternatively. the punch may have the form of a rod 28 of rounded cross section as seen in FIG. 10, with a tapered lower tip 29. A stop in the rod. as for example is provided at 30 by cross member 31 integral with the rod. is engageable with a shoulder 32 on the guide to limit relative downward travel of the rod in the guide.

The guide and rod may also have interengaged guide shoulders extending longitudinally for blocking relative rotation of the rod and guide. In FIG. 7, such shoulders are formed by the key 33 and keyway 34, the former carried by the guide section 110. and the latter formed by the rod section 14a. The keyway extends to the lower end of rod section to enable removal of that section from the guide after disconnection from section 14b.

In the method of attaching hangers 40 to the metal decking 26 as seen in FIGS. 1-4, a location is first selected as at 36 in FIG. 1 for forming a hole or slot in the decking. The lower opening 13 of the sleeve 11 is then placed on that location with the sleeve and rod extending upright. The sleeve and rod are also rotated to align the blade 16 in the lateral direction of the deck trough and the slot to be formed. as may be facilitated by observing the azimuth of the cross piece 31.

Next, the handle is lifted as to broken line position 15a in FIG 1 to elevate the punch and rod relative to the sleeve while maintaining the lower end of the sleeve in engagement with the decking at the selected slot location The handle is then dropped to drop the rod for developing momentum acting to propel the punch through the lower opening 13 and through the decking, as seen in FIG. 2. Dropping is limited by allowing cross piece 31 to engage upper shoulder 32; finally, the apparatus is lifted to remove the punch from the slot or opening 27.

As a result a flat metal strip hanger 40 may then be extending downwardly through the slot after the top of the hanger is deformed laterally by bending as at 41. The bend accordingly limits downward extension of the hanger. Cementitious material such as lightweight concrete 42 may then be poured over the decking to embed the hanger bend 41 and support same rigidly upon curing of the concrete. An air duct is shown at 44 attached to the supported hanger at 55 in FIG. 4.

FIG. 8 also shows releasable retention of the blade 16 in a slot 45 formed in the lower end of rod section 14c. Set screws 41 may be tightened in carrier sleeve 44 (threaded onto the rod section at 43) to engage and retain the blade in the position shown.

I claim:

1. In the method of attaching hangers to sheet metal decking. the decking forming a laterally extending trough. and wherein apparatus is employed to punch openings in the decking that extends generally horizontally. said apparatus comprising an elongated upright tubular guide having opposite open ends. an elongated metallic rod movable endwise in the guide and a handle on one end of the rod projecting from the upper end of the guide and a cross-piece on the rod above the guide. and a punch in the form ofa blade integral with the opposite and lower end of the rod, the steps that include a. selecting a location for forming a hole in the sheet metal decking and placing the punch tip on said location with the rod and guide extending thereabove rotating the punch and rod to orient the cross piece and thereby orient the blade in the direction of the trough and of an opening to be formed in the decking by the blade.

b. manually lifting the handle to elevate the rod and punch relative to the sleeve while maintaining the lower end of the sleeve in engagement with the decking proximate said location,

c. dropping the handle to drop the rod for developing momentum acting to propel the punch blade through the decking to form said opening therein at said location, guiding the rod to prevent rotation thereof during said dropping, limiting said dropping by allowing the cross-piece to engage the guide. and removing the punch from the opening. and

d. extending a hanger through said opening to be supported by the upper side of the decking. 

1. In the method of attaching hangers to sheet metal decking, the decking forming a laterally extending trough, and wherein apparatus is employed to punch openings in the decking that extends generally horizontally, said apparatus comprising an elongated upright tubular guide having opposite open ends, an elongated metallic rod movable endwise in the guide and a handle on one end of the rod projecting from the upper end of the guide and a cross-piece on the rod above the guide, and a punch in the form of a blade integral with the opposite and lower end of the rod, the steps that include a. selecting a location for forming a hole in the sheet metal decking and placing the punch tip on said location with the rod and guide extending thereabove, rotating the punch and rod to orient the cross piece and thereby orient the blade in the direction of the trough and of an opening to be formed in the decking by the blade. b. manually lifting the handle to elevate the rod and punch relative to the sleeve while maintaining the lower end of the sleeve in engagement with the decking proximate said location, c. dropping the handle to drop the rod for developing momentum acting to propel the punch blade through the decking to form said opening therein at said location, guiding the rod to prevent rotation thereof during said dropping, limiting said dropping by allowing the cross-piece to engage the guide, and removing the punch from the opening, and d. extending a hanger through said opening to be supported by the upper side of the decking. 